Striping machine



Aug. 2, 19 55 R. A. DONNAN QSTRIPING MACHINE 2 Sheets-Sheet .1

Filed Aug. 15, 1951 INVENTOR ROBERT A DONNAN ATTORN E 2, 1955 R. A. DONNAN 2,714,364

STRIPING MACHINE Filed Aug. 15, 1951 2 Sheets-Sheet 2 2; La 46 F|G.9 w 7? 2 /,Q l lllllllllflllllllll 43 S2\ 15 FIG. l4

l2 5 TI W INVENTOR ROBERTA.DONNAN s" ATTORNEY United States Patent STRIPING MACHINE Robert A. Donnan, Worcester, Mass., assignor to Surprenant Mfg. Co., Boston, Mass.

Application August 15, 1951, Serial No. 242,009 12 Claims. (Cl. 118-422) This invention relates to a striping machine for applying spiral identification marks or stripes to elongated objects such as the insulation of electric conductors.

The invention to be set forth hereinafter is for a machine of the general type shown in Forsberg Patent No. 2,537,884 wherein the object to be striped moves vertically along the axis of a rotatable head :on which striping disks are mounted for engagement with and rotation by the object. A machine of this kind is called upon from time to time to stripe conductors of different diameters and it is the general object of the invention to provide mountings for the striping disks which enable the latter to be quickly adjusted to accommodate conductors of ditferent'sizes.

The thickness of insulation on an electric conductor may vary along its length due to unevenness of operation of the extruding machine which applies the insulation and it is a further object of the invention to mount the striping disks so they can adapt themselves to variations in diameter of the insulation and produce continuous stripes on those parts of the insulation which may be slightly smaller or larger than the normal diameter of the insulation.

It is a still further object of the invention to provide at least three striping disks to engage and center the conductor being striped and make the disks as parts of striping units which are free, within a limited range, to rotate about pivots on the machine parallel to the machine axis. An equalizer connecting all the units together causes them to move in unison about their pivots.

It is an important object of the invention to construct the aforesaid striping units so they normally tend to :hold the disks a slight distance away from the axis of the machine when the latter is running, and apply a small force to the units to displace them away from the position they tend to assume in a direction to cause a light pressure engagement of the disks with the conductor or other object being striped. Centrifugal force plays a part in the tendency the units have to assume their normal position with the disks spaced from the conductor being striped, but this force is overpowered by a means, such as a spring, which urges the disks against the conductor. Adjustable counterweights on the striping units permit an adjustment of the amount of centrifugal .force acting on the units, and an adjustment for the spring permits a variation in the force it exerts. The actual net force acting on the disks is the difference between the spring and centrifugal forces.

It is another object of the invention to aiford an adjustment between each striping disk .and its striping unit to enable a stripe on the conductor to be shifted toward one of the other stripes when an unequal spacing of the stripes is desired to facilitate direction of reading of the stripes.

It is a still further object of the invention to provide an improved striping unit including a bearing, an adjustable counterweight thereon, and a striping disk support ice permitting adjustment of the distance between the axis of the unit and the striping disk on the support.

Still another object of the invention is to provide an assembly comprising a cover plate for the .head of the machine and striping units pivotally mounted on the cover plate, the assembly as a whole being fitted .easily to the head.

Three striping disks are shown in the accompanying drawings, but the invention is not limited to this number of disks, and although the disks are all shown of the same width, narrow and wide rim disks can be used to produce .narrow and broad stripes on the same conductor when desired.

In order that the invention may be clearly understood reference is made to the accompanying drawings which illustrate by way of example the embodiments of the invention and in which:

.Fig. l is a plan view of the stripinghead,

Fig. 2 is an enlarged vertical section on line 22, Fig. 1,

Fig. 3 is a horizontal section on line 33, Fig. 2,

Fig. 4 is a vertical section on line 44, Fig. 2, parts being broken away, i

Fig. 5 is a horizontal section on line 5.5, Fig. 2, parts of the striping rollers or disks being broken away,

Fig. 6 is an enlarged fragmentary vertical section on line 6-6, Fig. 2,

Fig. 7 is a fragmentary vertical section on line 77, Fig. 6,

Fig. 8 is a detail vertical section on line 88, Fig. '2,

Fig. 9 is a detail vertical section on line 99, Fig. 2, showing the manner of mounting the counterweights,

Fig. 10 is a perspective view of one of the supports for a striping disk detached from its striping unit,

Fig. 11 is a central vertical section through part of the cover plate of the striping head and showing a gauge for setting thestriping disks,

Fig. 12 is a detail horizontal section on line 1212, Fig. 11,

Fig. 13 is an elevation of a wire with the insulation thereof having helical stripes thereon such as are produced by the disks of the striping head, and

Fig. 14 is a diagrammatic :side elevation of a striping machine made according to the :present invention and showing the driving motor.

The striping machine to be set forth in detail herein after is for the purpose of producing variously color helical identification stripes on an elongated object W, which may be an electric conductor having insulation 1 on an electric wire 2, 'see vFig. 12. The insulation is generally cylindrical in form, but may have sections along its length which are thicker or thinner than its normal diameter, as indicated for instance at 3 and 4. These variations .in diameter are exaggerated in Fig. 12 and the striping machine should be able to produce continuous stripes on both the thick and thin parts as well :as those parts of normal diameter. Fig. 12 shows but one "insulated conductor, but it is to be understood that the machine is adapted for use with conductors of different normal diameters.

Fig. 14 shows a motorS supported on a stand 6 and a driving belt 7 trained around a driving pulley 8 "on the motor and a driven pulley 9 on a hollow upright shaft '10. The latter turns in upper and lower bearings 11 and 12, respectively, mounted on the stand. The upper bearing is shown in Fig. 2. The wire Wis moved vertically along the axis of the shaft in timed relation with the rate of rotation of the latter by feed mechanism (not shown herein).

As shown in Fig. 2 the upper end of the shaft has secured thereto a striping head designated generally at H. The head includes a vertically elongated part 15 in which to the axis of the machine.

are. located in the present instance three ink wells 16, 17 and 18, which open upwardly into inking compartments or chambers 19, 20 and 21, respectively, see Fig. 5'. As the head H rotates ink in the wells rise by con trifugal force into the outer parts of the compartments and remain spaced from the wire W. The compartments are interconnected and contain the striping rollers or discs 22, 23 and 24.

Much of the matter thus far described may be similar to the striping machine shown in the aforesaid Forsberg patent. In operation, the disks are revolved around the axis of the machine as head H turns and are rotated by rolling engagement with the wire W as the latter moves along the axis and in turning are inked for the striping operation by ink in the outer parts of the compartments.

The present invention relates more particularly to striping units on which the disks are mounted, and means for controlling the units. These units, designated at U1, U2

and U3 in Fig. 1, are mounted on a cover plate secured by screws 31 to the top of part 15 of head H and forming part of the head. Secured to and extending upwardly from the cover plate are screws 32 having their axes parallel to the axis of the machine. Each of these screws is fitted to an inner shell 33 against which lie anti-friction rollers 34 located within an outer shell 35. Each screw 32 has a head 36 over the shells and rollers to hold them in place. The screws 32 and their inner shells and rolls may be considered as pivots for the striping units.

The striping units U1, U2 and U3 are all alike and only one of them will be described in detail, namely, unit U1 associated with disk 22.

Unit U1 comprises a circular bearing 40 secured to and concentric with the associated outer shell and supported by the out-turned flange 41 at the bottom of the corresponding inner shell, see Figs. 2 and 7. Thelower part 42 of bearing is of relatively large diameter while the upper part 43 is of reduced diameter. Resting on the large part 42 and closely fitted to but rotatable on the upper part 43 concentrically about the axis of bearing 40 is a ring 44 into which is tapped a weighted member or counterweight screw 45 having adjustable therealong two nuts 46 above the cover plate which lock each other in adjusted position. The screw 45 is set up tight against the reduced upper part 43 of bearing 49 to hold the ring in circularly adjusted position on the bearing 40. The ring 44, screw 45, and nuts 46 constitute an adjustable counterweight C, Fig. 9, the nuts being adjustable radially with respect to the axis of bearing 40 and the counterweight being adjustable angularly on the bearing by reason of screw 45.

.-The lower part 42 of bearing 40 is formed with a slot 50 into which fits a horizontal arm 51 of a disk support S. The under side of arm 51 has a downwardly opening slot 52 therein through which extends a setting screw 53. The screw is tapped into bearing 40, see Fig. 6, and its head 54 clamps arm 51 against the bearing. Slot 52 is long enough to permit some lengthwise adjustment of arm 50 transversely of bearing 40.

Support S has a depending arm 55 rigid with arm 51 and terminating in a horizontal foot 56. Depending arm 55 passes downwardly through a hole 57 in the cover plate 30 large enough topermit some freedom of horizontal swinging movement of arm 55.

The foot 56 has one surface 58 thereof inclined in a plane directed upwardly and away from arm 55. A stud 59 is screw threaded into the foot perpendicular to surface 58 and serves to mount the striping disk 22 for rotation in a plane oblique to the axis of the machine. The bearing 40, counterweight C, support S and the striping disk 22 constitute the striping unit U1 which is freely rotatable on its pivot in a horizontal plane perpendicular All the units are alike and are rotatable relatively to the head H in substantially the same plane.

The cover plate 30 has a vertically extending hole 60 therethrough coaxial with the axis of the machine when the cover plate is in place on the head. This hole is screw threaded at 61 to receive the screw threaded barrel 62 of a gauge G. A cylindrical stem 63 of the gauge will extend down far enough to engage the striping disks when the gauge is temporarily in the position shown in Pi g. 11 and will be coaxial with the machine.

After the gauge is in place and the striping units ar on their pivots the setting screws 53 will be loosened to permit the arms 51 to he slid along slots 56 until the peripheries of the striping disks are in proper tangential engagement with stem 63. The setting screws are then tightened, and assurance is given that when any striping unit is swung around its pivot counterclockwise, Fig. 1, the corresponding striping disk will correctly contact stem 63, or any wire lying along the machine axis. The pivot of each striping unit is so located that as the corresponding disk approaches the machine axis that part of the periphery of the disk nearest to the axis moves in a direction almost at right angles to a line joining the machine axis and the associated pivot, see Fig. 1. All the disks when engaging a wire will engage it at the same position along its length to center the wire and prevent it from vibrating when the machine is in operation.

Fig. 13 shows three helical stripes a, b and 0 equally spaced along the wire W a relation which will be produced if all the disks are so mounted that their points of tangency with the wire are exactly 120 degrees apart measured around the machine axis. It may be desirable, however, to change the spacing of the helical stripes, in which case one of the setting screws 53 can be loosened and the corresponding arm 51 can he slid endwise in its slot 50 until the periphery of the associated disk is nearer to one of the other disks than to the third disk. Thus, if it be desired to shift thestripe made by disk 22 toward the stripe made by disc 24, arm 51 of unit U1 would be moved to the left, Fig. l.

The adjustments of the striping units and disks already described may be made most conveniently with the cover plate 30 removed from the head H and inverted. The gauge G will of course be removed from the cover plate and the latter replaced on the head before a striping operation is started.

After the disks have been adjusted and the cover plate replaced on the head, the counterweights are given an approximate adjustment. This may be done by fastening all the counterweights to their striping unit in the same position relative to the units and then starting the rnotor. By looking down through the screw threaded hole 60 in the cover plate the peripheries of the disks nearest the machine axis will be seen to describe circles around the axis. By careful adjustment of the counterweights the circles described bythe disks can be made to merge into a single circle, indicating that all the disks are at the same distance from the machine axis.

The counterweights are preferably set so the circle described by the peripheries of the disks will be slightly larger than the largest conductor which the machine will be called upon to stripe. This adjustment of the counterweights should be made before the spring 75 to be described hereinafter is fastened to the cover plate.

, When the adjustment is. completed the striping units will tend to occupy positions relative to head H such that the disks will be spaced from the axis of the machine when the machine is running at speed.

In order that the striping units may turn in unison and to the same degree on their pivots there is provided an equalizer E, Fig. 1, comprising a wire the ends of which are connected to a turnbuckle 71 which is shown herein as one means of keeping the wire 70 taut. Each bearing 40 has a peripheral groove 72 therein to receive the wire 70 and has tapped thereinto a clamping screw 73 the head 74 of which clamps the equalizer wire against the bearing when the screw 73 is fastened in place. The equalizer is connected to the bearings when all the disks are touching the stem 63 of the gauge '6, after which the striping units will always have their striping disks equally spaced from the machine axis.

Means is provided to apply a force to the striping units tending to turn them counter-clockwise, Fig. 1, or in a direction to move the disks toward the machine axis. As shown in Fig. 1 this means comprises a leaf spring 75 having the outer end thereof held by a small screw 76 tapped into the cover plate 30, and having its inner free end 77 hearing against arm '51 of the striping unit Ul. An eccentric 78 adjustable angularly on the cover plate engages the spring between its ends and affords means for varying the force exerted by the spring on the arm 51 engaging it.

When a striping operation is to be performed the inks of the desired colors will be poured into the wells 1618 and the cover plate secured in position. Spring 75 will tend to move the disks toward the machine axis into en gagement with each other, but by manually turning one of the striping units clockwise, Fig. l, the disks can be moved away from the axis and the elongated object or conductor W can then be passed up through the hollow shaft and led through a drying tower to a take-up (neither of which is shown herein). Release of said one striping unit will be accompanied by movement of the disks against the conductor W by spring 75. i

The driving motor will then be started and the head H will rotate as the conductor W moves along the machine axis. Ink will rise from the wells into their corresponding compartments due to centrifugal force and ink the striping disks. Thecharacter of the conductor W rising from the machine, assuming upward feed of the conductor, will indicate whether the disks are striping correctly. If no stripes are produced this will be due to the fact that the counterweights are set in such positions on the bearings that they act by centrifugal force to overpower spring 75 and prevent it from holding the disks against the conductor W. Thiscondition can be remedied by moving the nuts 46 in toward the pivots, or loosening screws and turning the rings 44 on the bearings 40 to a-diiferent position and then tightening the screws 45. If, 'on the other hand, the stripes on the conductor suggest that the disks are being forced too strongly against the conductor, opposite adjustments of the counterweights will'be made. Several trials of adjustment may be necessary to attain most favorable striping conditions, but once the correct setting of the counterweights has been made it is unlikely that further adjustments will be needed, even if conductors of different diameters are striped in later operations of the machine.

When the machine is running correctly at full speed the counterweights will tend to ,position the striping units relative to the head H so that the disks will be spaced slightly from the conductor, but the spring 75 will counteract this tendency and hold the disks in tangential rolling engagement with the moving conductor .to enable the latter to turn the disks on their axes through the ink in the outer parts of the compartments. The net force which holds the disks against the conductor is the difference between the force exerted by spring 75 tending to move the disks toward the machine axis and the collective force exerted by the counterweights tending to move the disks away from the axis.

If a thick place 3 in the conductor arrives between the disks it will exert a spreading or separation .force on the disks tending to move them away from the machine axis. The counterweights will tend to assist the separation force insofar as they are permitted to do so by spring 75. A thin place 4 arriving between the disks will be accompanied by a movement of them toward the machine axis by spring 75. In either event the disks will produce stripes on the thick and thin places which are continuous with the stripes on the parts of the conductor of normal diameter.

When a conductor of small diameter is to be striped the eccentric 78 will be adjusted to increase: the force exerted by spring to displace the striping units from the normal angular position relative to the head they would occupy under speed due to the counterweights. When conductors of large diameter are to be striped the eccentric can be turned to reduce the force of the spring, since under this condition only a slight displacement of the striping units from their normal angular position is required to produce a satisfactory stripe.

From the foregoing it will be seen that the invention provides a striping machine having striping units rockable about axes or pivots parallel to the axis of the machine so that the disks can accommodate conductors of different diameters. The striping units are provided with counterweights which can be set to make the units tend to assume positions relative to the head H in which the disks are spaced from the machine axis when the machine is running. The spring 75 displaces the striping units from the positions they tend to occupy sufficiently to hold the disks against the conductor. The spring and the counterweights exert opposing but yielding forces on the units and are preferably adjustable to enable the machine to stripe conductors of different diameters, and also to adjust the net force holding the disks against the conductor. Furthermore, the invention provides a simple striping unit having a bearing and a counterweight and a striping disk support which can be adjusted to shift a stripe on the conductor with respect to the other stripes. Although three striping disks have been shown, more may be used if desired, but in any arrangements of disks they should be spaced angularly from each other around the machine axis by less than degrees and should engage the conductor at the same position along its length to center it. Also, the invention sets forth an assembly readily applied to the head H and comprising the cover plate 34) and the units U1, U2 and U3 thereon. The bearings 30 and counterweights Care above the cover plate while the striping disks are below it. Also, the support for each disk is adjustable relatively to its bearing to permit a change in distance from the axis of the bearing to that part of the periphery of the disk nearest to the axis of rotation to enable the disk to produce a stripe which may be offset slightly from its normal position. Furthermore, the equalizer Wire E moves relatively to the head angularly around the axis of rotation when the bearings turn on their pivots, thereby enabling the disks to be spread apart for insertion of a new wire to be striped merely by moving the wire E.

Having now particularly described and ascertained the nature of the invention and in what manner the same is to be performed, what is claimed is:

1. In a striping machine having a vertical axis along which moves a wire to be striped during operation of the machine, a head mounted for rotation about said axis comprising at least three ink compartments radiating from said axis, driving means to rotate the head about said axis, a cover plate secured to said head over said compartments, a pivot corresponding to each compartment fixed to and extending upwardly from said plate and parallel to said axis, a plurality of similar striping units, one unit for each pivot, each unit comprising a bearing movable angularly on the associated pivot in a plane perpendicular to said axis and a striping disk below said plate in the associated compartment rotatable on the unit having part of the periphery thereof moved either toward or away from said axis by the unit as the latter turns on the pivot therefor relative to said head, depending upon the direction of turning of the unit onthepivot, the angular distance from any disk to 'the disk on either side thereof measured around said axis being less than 180 degrees, an equalizer above said plate connected directly to said bearings and moving angularly around said vertical axis when the bearingsturn 7 on their respective pivots, and means cooperating with the equalizer tending to move said equalizer angularly around said vertical axis to turn all of the units on their pivots in a direction to move the striping disks toward the same position along said axis.

2. The striping machine set forth in claim 1 wherein the equalizer is a wire secured to the bearings of the units.

3. In a striping machine having a vertical axis along which moves a wire to be striped during operation of the machine, a head mounted for rotation about said axis comprising at least three ink compartments radiating from said axis, driving means to rotate the head about said axis, a pivot corresponding to each compartment fixed to the unit and parallel to said axis, a plurality of similar striping units, one unit for each pivot, said units being movable angularly on their pivots in a plane perpendicular to said axis, each unit comprising a striping disk extending into the associated compartment and rotatably mounted on the unit and moved by the latter when the unit turns on its pivot either toward or from said axis, depending upon the direction of turning of the unit relative to the head, each unit being moved by the pivot therefor bodily around said axis when the head rotates, a counterweight on each unit effective due to rotation of the head to exert a given force tending to hold the periphery of the corresponding disk spaced from said axis and without appreciable tendency to rotate on the pivot when said driving means rotates the head, an equalizer connecting the units causing the latter to turn in unison about their respective pivots, and resilient means cooperating with said equalizer exerting a force in opposition to and greater than the sum of said given forces tending to turn all of said units in a direction to move the disks toward the same position alongsaid axis said resilient means yielding to enable the units to move away from said axis in the event they engage a thickened part of the wire, the angular distance from any disk to the disk on either side thereof measured around said axis being less than 180 degrees.

4. In a striping unit for a striping machine having an axis of rotation and a pivot the axis of which is spaced from but parallel to the axis of rotation, a bearing to fit and turn on the pivot, a ring supported by the bearing normally fixed with respect thereto but adjustable angularly on the bearing around the axis thereof, a counterweight secured to said ring and extending from one side of the bearing, a support secured to and extending from the other side of the bearing, and a striping disk rotatably mounted on said support.

5. A striping unit as set forth in claim 4 wherein the counterweight includes a screw tapped into the ring and against the bearing to hold the ring and counterweight in adjusted angular position on the bearing.

6. A striping unit as set forth in claim 4 wherein said support includes an arm on which the disk is rotatably mounted extending laterally from the bearing and adjustable securing means is capable of holding the arm to the bearing in any one of a plurality of positions to vary the distance from the axis of the bearing to that part of the periphery of the disk nearest to said axis of rotation.

7. A striping unit as set forth in claim 4 wherein said support includes an arm on which the disk is rotatably mounted having a slot therein and a setting screw extends through the slot and is tapped into said bearing and affords means for holding the arm to the bearing in any one of a plurality of positions to locate that part of the periphery of the disk nearest to said axis of rotation at different distances from the axis of the bearing.

8. In a striping machine having a vertical axis along which moves a wire which may have thick and thin places occurring along its length, a head mounted for rotation about said axis comprising at least three ink compartments radiating from said axis, driving means to rotate the head about said axis, a pivot corresponding to each compartment fixed to the unit and parallel to said axis, a plurality of similar striping units, one unit for each pivot, said units 8 being movable, angularly on their pivots in a plane perpendicular to said axis, each unit comprising a striping disk extending into the associated compartment and rotatably mounted on the unit and moved by the latter when the unit turns on its pivot either toward or away from said axis, depending upon the direction of turning of the unit relative to the head, each unit being moved by the pivot therefor bodily around said axis when the head rotates, and two different means exerting opposed yielding forces on each unit when the head rotates tending to cause the unit to turn on the pivot therefor, one of said means being a counterweight on the unit tending due to centrifugal force when the head rotates to yieldingly hold the unit with the disk therefor spaced from said axis, and the other means exerting a yielding force on the unit in opposition to and overpowering the first means and eifective to turn the unit on its pivot in a direction to move the disk toward said axis and against the wire being striped, the second means causing the disk to move toward said axis to remain in contact with a thin'part of the wire, and said second means yielding and said first means tending to move the disk away from said axis when the disk engages a thick part of the wire.

9. In a striping machine having a vertical axis along which moves a wire to be striped during operation of the machine, a head mounted for rotation about said axis comprising at least three ink compartments radiating from said axis, driving means to rotate the head about said axis, a pivot corresponding to each compartment fixed to the unit and parallel to said axis, a pluralityof similar striping units, one unit for each pivot, said units being movable angularly on their pivots in a plane perpendicular to said axis, each unit comprising a striping disk extending into the associated compartment and rotatably mounted on the unit and moved by the latter when the unit turns on its pivot either toward or from said axis, depending upon the direction of turning of the unit relative to the head, each unit being moved by the pivot therefor bodily around said axis when the head rotates, a counterweight on each unit effective due to rotation of the head to exert a given force tending to hold the periphery of the corresponding disk spaced from said axis and without appreciable tendency to rotate on the pivot when said driving means rotates the head, an equalizer connecting the units causing the latter to turn in unison about their respective pivots, and means cooperating with said equalizer acting in opposition to and greater than the sum of said given forces tending to turn all of said units in a direction to move the disks toward the same position along said axis, said cooperating means comprising a spring mounted on the head and engaging one of the striping units, and the angular distance from any disk to the disk on either side thereof measured around said axis being less than 180 degrees.

10. In a striping machine having a vertical axis along which moves a wire to be striped during operation of the machine, a head mounted for rotation about said axis comprising at least three ink compartments radiating from said axis, driving means to rotatethe head about said axis, a pivot corresponding to each compartment fixed to the unit and parallel to said axis, a plurality of similar striping units, one unit for each pivot, said units being movable angularly on their pivots in a plane perpendicular to said axis, each unit comprising a striping disk extending into the associated compartment and rotatably mounted on the unit and moved by the latter when the unit turns on its pivot either toward or from said axis, depending upon the direction of turning of the unit relative to the head, each unit being moved by the pivot therefor bodily around said axis when the head rotates, a counterweight on each unit efiective due to rotation of the head to exert a given force tending to hold the periphery of the corresponding disk spaced from said axis and without appreciable tendency to rotate on the pivot when said driving means rotates the head, an equalizer connecting the units causing the latter to turn in unison about their respective pivots, and means cooperating with said equalizer acting in opposition to and greater than the sum of said given forces tending to turn all of said units in a direction to move the disks toward the same position along said axis, the angular distance from any disk to the disk on either side thereof measured around said axis being less than 180 degrees, said means cooperating with said equalizer comprising a spring and means to vary the force exerted by the spring.

11. In a striping machine having a vertical axis along which moves a wire which may have thick and thin places occurring along the length thereof, a head mounted for rotation about said axis, driving means to rotate the head about said axis, a plurality of similar striping units each comprising a striping disk inked during operation of the machine rotatably mounted on the unit, a pivot on the head for each unit around which the latter can swing to move the disk therefor toward and from the axis, each unit being revolved bodily by the pivot thereof around said axis when the head rotates, and two different means exerting opposed yielding forces on each unit tending to cause the unit to turn on the pivot thereof when the head rotates, one of said means being a counterweight on the unit tending due to centrifugal force when the head rotates to yieldingly hold the unit with the disk thereof spaced from said axis, and the other means exerting a yielding force on the unit in opposition to and overpowering the first means and effective to turn the unit on its pivot in a direction to move the disk toward said axis and against the wire being striped, the second means causing the disk to move toward. said axis to remain in contact with a thin part of the wire and yielding to enable the disk to move away from said axis when engaging a thick part of the wire.

12. A striping machine as set forth in claim 11 wherein an equalizer is connected to the units and causes them to rotate in unison on their pivots in response to either of said yielding forces.

References Cited in the file of this patent UNITED STATES PATENTS 2,007,729 Shallcross July 9, 1935 2,344,610 Hargreaves et a1. Mar. 21, 1944 2,537,884 Frosberg Jan. 9, 1951 2,581,180 Entwistle et a1. Jan. 1, 1952 2,592,667 Donnan Apr. 15, 1952 2,592,674 Forsberg Apr. 15, 1952 

